A galaxy is a collection of stars and other astronomical bodies, including planets, comets andasteroids, held together by gravity.
Galaxies come in different shapes and sizes. These include the spiral, barrel-spiral and
elliptical. Our galaxy called the Milky Way, is approximately 100 000 light years in the width and
contains over 100 billion stars.
The centre of galaxies can contain many young, very hot stars as well as older stars. Swirling
clouds that have been energised by magnetic forces also exist in the centre.
At this point in time, no one knows the exact number of galaxies in the universe.
Astronomers are, however, learning more and more about them every day.

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44. What's the writer's purpose to write the text?
45. What are astronomers doing right now?​